Biden's been rejected by his own party, rejected by the voters, his reputation is trashed, his son is facing prison, he's probably less than a year from dying of old age. He's an embittered lame duck with nothing to lose and a grudge against the world. Unlike Carter, he doesn't have any time left to repair or rehabilitate his reputation and legacy.
Now, after refusing to allow Ukraine to use long-range U.S. weapons to strike targets "deep inside" Russia for the last two years --- stating that it could result in nuclear retaliation leading to WWIII --- he just changed his mind 60 days before he leaves office. Even the director of communications for Hillary Clinton's 2016 campaign is horrified.